What Is a 10-Ply Tire?
Though this older term can be a familiar way to reference a heavier-duty tire, you'll want to know the modern equivalent when shopping for new rubber.
Shutterstock
QuickTakes:
When shopping for a truck tire, you may encounter references to 10-ply tires. This outdated term still hangs on for some reason and may have you asking questions such as: What is a ply? Is 10 a lot? How many plies do I really need?
It's worth breaking all of this down and demystifying truck tire load ratings in the process.
A Ply Is Another Name for Layers in a Tire
Beneath the tread, a tire has multiple layers — made of materials including steel, polyester, and special polymers called polyamides — that provide its inner structure. Each of those layers is a ply.
In the olden days, tires used so-called bias-ply construction, wherein the first ply was laid at an angle (or bias) to the tread, followed by another ply laid at an alternating angle. The more plies, the stronger the tire and the more load it could handle.
Today, most vehicles use radial tires, where the plies run perpendicular to the tread (that is, from bead to bead). Compared with bias ply, radial construction adds stability to the tire, resulting in a smoother ride and less tendency to follow ruts or other road imperfections.
While 10-Ply Tires Have 10 Layers, Newer Equivalents May Not
A true 10-ply bias-ply tire has — you guessed it — 10 plies. But counting these layers is no longer meaningful in the age of radial tires, as there is no direct correlation between the number of radial plies and tire strength; the type of plies and specifics of the construction determine how the tire behaves. You can, however, still find information on the sidewall about the number and type of plies used to construct a tire.
Because of this, light truck tire load ratings are now represented by letters instead of ply counts, despite the new system having its basis in the old. The load of a B-rated tire is equivalent to what an old four-ply could manage. C corresponds to a six-ply tire, D to an eight-ply, E to a 10-ply, and F to a 12-ply. (There is no A.)
And while it's outdated, some people like to interchange the two codes. For instance, they might refer to the 2023 Jeep Wrangler Rubicon's C-rated radial tires as six plies, even though the sidewall shows it has only five. The rating system equates a C-rated tire with the older six-ply tires when it comes to how much load they can handle safely. Newer tire technology means that tire manufacturers can often achieve the same performance with a radial tire with fewer plies than they could with bias-ply tires.
Choosing a Tire With the Correct Load Rating
You don't need to know anything about plies to pick the correct light truck tire. The main thing to remember is that the new rubber should match or beat the load rating of the original equipment.
Going with a higher load rating than necessary may provide more durability, but it is also likely to result in reduced ride comfort, as the extra reinforcement prevents the tire from giving. Remember, though, it's unsafe to carry more load than a vehicle was originally rated and designed for, meaning that a higher load rating for tires won't increase the vehicle's weight-carrying ability.
